Erasing attachment for typewriters



April 5, 1938. .wlLNl-:Rq n2,113,437

ERASING ATTACHMENT FOR TYPEWRITERS n FiledMarCh 25, 1956 3 Sheets-Sheet 1k 26 ..lll

INVENTOR. L ol//s Wu. Nee,

am it ATTORNEYS April 5, 1938. L. WILNER ERASING ATTACHMENT FOR TYPEWRITERS Filed March 25, 1936 s. sheets-sheet 2 ATTORNEYSy April s, 1938.

L. WILNER ERASING ATTACHMENT FOR TYPEWRITERS .Filed March 25, 1936 3 Sheets-Sheet 5,

fm s 1 33 hlm QQ S E [Hnl- V B INVENTOR.

ATTORNEYS .Patented Apr. 5, 1938 UNITED STATES PATENT oei-fics n .4 omm- (ci. 1p1-,1an

'I'his invention relates to typewriters and other v writing machines or adding machines and refers more particularly to an erasing device for typewriters.

An object of the present invention is the provision of a simple and eectively operable mechanism for obliterating improperly written typel characters, which mechanism may be convenient- 1y incorporated in a typewriting machine of any standard make.

Another object is the provision of a type-` writing machine having an attachment, through the use of which errors in typewriting may be quickly and easily corrected by erasure while the paper remains in position on the machine.

A further object of the present invention is the provision of an erasing device which constitutes an integral part of the typewriting machine, and which is automatically operable by the depression of a key to move backward the platen carrying the paper and thereupon to move an eraser over the letter or character to be obliterated. i

'I'he above and other objects of the present invention may be realized through the provision of an eraser removably mounted upon a rod and pressed by resilient means against the paper carried by the platen. f

The rod is reciprocated in the vertical direc- 'I'he invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawings, showing, by way of example, a preferred embodiment of the inventive idea.

In the drawings;-

Figure l shows in front elevation a typewriter provided with erasing device; l

Figure 2 is a section along the line 2--2 of Figure l, with parts broken oi.

Figure 3 is a front elevation of the erasing attachment on a larger scale with some ,parts broken away;

.means of the handle I3.

Figure 4 is a section-along the line l-lfof Figure 3;\ f

Figure 5 is a top view ofthe device illustrated in Figure 3 Figure 6 is avperspective view of the vertical bar carrying the eraser;

Figure 7 is a section through the portion of the bar carrying the eraser;

Figure 8 is a top/ view of the backk spacing mechanism;

Figure. 9 is a section along the lineal-3 of Figures8and10;

Figure 10 is a side view of mechanism. .c v

IThe typewriter illustrated -in the drawings is a standard construction. This typewriter is shown merely by way of example, since 'the erasing attachment constituting the subject-matter of the present invention may be used in connection with typewriters of any type or make.

'I'he illustrated typewriter comprises ay frame i3 carried by the supports Il and provided with the movable carriage i2. The platen i3 which -is movable along with the carriage is mounted on brackets I4 and i5 and may be rotated by The carriage is provided with roller clamps l'l and I3 which press the paper against the platen, and with vthe line the back spacing spacer I9. A paper rest 2l constitutes a part of the carriage and surrounds the lower por' tion of the-platen i3. The carriage IZ'ismovablealong with its support 2| which is guided by the guide bars 22 rigidly attached to the frame.

The'typewriter ribbon 23'is carried by the ribbon spools 2l and 2l which are mounted upon pivots 26 and 21 carried by the horizontal bars 23 and 23, respectively.

Aplate or guide 33 for the type bars is attached to the frame of the typewriter and is' provided witha suitable slot 3i through which the type' carried by a type bar 33 strikes the ribbon 23 situated in front of the paperi-not shown) and the platen I 3.

Afmovable ribbon carrier 32 is situated between the platen I3 and the guide 30. The device which moves the ribbon carrier 32 upward so that it is situated in the path of the type when the latter passes through the' slot 3| is not shown in the drawings and is 'of standard make. This device moves the ribbon 23 upward as soon as the operator depresses one of the keys, so that by the time the type reaches the slot 3| the ribbon is situated Vbetween the type and the papercovering the platen i3, so that r usl the type leaves the impression of the ink carried by the ribbon'23 upon the paper.

The typewriter is provided with typing keys 33 carried by the ends of the key levers 34.

The key lever 34a (Figure 2) is provided with an ear 33 and is pivotally mounted upon a rod 33. 'I'he opposite end of the key lever 34a is connected with a link 31 which is attached to a type bar 33 carrying the type 33 and pivotally mounted upon the pivot 43. Other key levers 34 are similarly constructed. l

In the normal inoperative position shown in Figure 2 of the drawings the type bars 33 rest upon a support 4| which is rigidly connected with the frame I3, while the key bars 34 rest upon ythe rod 42 which is also firmly connected with the frame I3.

When the key 33a is depressed by the operator. the key bar 34a swings around its pivot 33 so that the link 31 pushes upward the type bar 33 and thereby moves the type 33 into the slot 3| of the guide plate 33.- At the same time the ribbon supporting device 32 is moved upward so that the type 33 strikes the ribbon 23 and leaves an impression upon a sheet of paper which covers the platen I3. Thereupon the carriage I2 and the platen I3 supported thereby are moved one space to the left (looking in the direction of Figure 1) by the mechanism of the usual type which is not shown in the drawings. Finally, the type bar 33 and the key bar 34a are moved back to their original positions illustrated in Figure 2 by resilient means not shown in the drawings.

The back space key 42a is carried by one end of a horizontal lever 43 which extends to the rear of the can'iage and which is pivoted at 33 (Figure l0). The rear end 3| of the lever 43 is in engagement with an arm 32 (Figure 9) pivoted at 33 and having a projection 34 which engages a slanting surfaces 33 (Figure 8) of the lever 44. The lever 44 is provided with a hook 43 and has a slot 43 through which passes the pivot 41. The depression of the back space lever 43 is transmitted by the projection 34 of the arm 32 to the surface 33 of the lever 44, the hookshaped end 43 of which is brought into engagement with a rack 43 carried by the movable carriage I2 which supports the platen I3 (Figures 2 and 4). The mechanism actuatingthe lever 44 causes the hook to carry out an oscillatory movement, in the course of which the carriage and the platen I3 are moved one space to the right (looking in the direction of `Figure l). At the end of this movement the hook 43 is in engagement with an adjacent tooth of the rack 43.

The above-described typewriter is of the standard type and does not constitute a part of the present invention.

In accordance with the presentinvention, the typewriter comprises an erasing attachment which constitutes an integral part ofthe type- `writer, and which is actuated by the depression of the key 33 shown in Figures 1 and 2. 'I'he key 33 is attachedto thevertically bent end of a substantially horizontal key bar 3| provided with a curved middle portion 32 which extends over the support 42. The key bar 3| is provided with an ear 33 extending from the upper side thereof. A pivot 34 passes through the ear 33 so that the key bar 3| is oscillatable around the lpivot 34. A second smaller ear 33 is situated on the 'opposite lower side of the key bar 3| and carries one end of the coil spring- 33, the opposite end of which is attached at 31 to the frame I3 of the typewriter. The opposite end of the key bar 3| is pivotally connected at 33 with an ear 33 con stituting a part of a vertical eraser bar 33. The bar 33 extends between the vertical portion I 3a of the frame I3 and the support 3| carrying the shaft 40 upn which the type bars 33 are rotatably mounted.

The vertical bar 33 is provided with a diagonally bent portion 33a and an upper vertical portion 33h extending between the platen |3 and the guide plate 33 at a short distance from the movable ribbon support 32.

The upper end ofthe rod 33 is illustrated on a larger scale in Figures 6 and 7 of the drawings; this end is bifurcated and comprises two substantially flat prongs 32 and 33 separated by a vertical slot 34 and interconnected by the eraser casing 33 which is of trapezoidal form in cross-section, asl shown in Figure 7. An eraser 33 is situated in the casing 33 and may be held therein by friction or by any suitable stop not shown in the drawings. The eraser 33 may be of any standard make and is provided with an operative surface 31 which projects beyond the Vprongs 32 and 33 and which is passed over the surface of the paper by the actuation of the key 33 to erase a typed character. Any suitable abrasive may be used to provide the surface 31.

'Ihe eraser 33 may be conveniently removed from its casing 33 and replaced by a new one, whenever necessary.

As shown more clearly in Figure 3, the eraser is pressed against the platen I3 and the paper covering the same by two leaf springs 33 and 33. 'I'he leaf spring 33 presses against the prong 32 while the leaf spring .33 is pressed against the prong 33. 'I'he leaf spring 33 is carried by a vertical support 13, the lower end of which is firmly connected with the guide 33. Similarly, the leaf spring 33 is carried by a support 1| which is also attached to the guide 33. 'Ihe eraser casing 33 is guided by the leaf springs 33 and 39 during its movement.

The leaf springs 33 and 33 press the prongs 32 and 33 against the platen I3 in all positions of the eraser bar 33. However, in the inoperative position of the device the eraser 33 carried by the casing 33 issituated below the springs 33 and 33 so that the type 33 can pass conveniently through the slot 3| formed in the guide plate 33 and through the slot 34 provided between the bifurcated ends 32 and 33 of the eraser bar 33, thus reaching the ribbon 23 and making an impression upon the paper covering the platen I3.

The eraser attachment is operated in the following manner.

When the part of the paper provided with the letter or the character to be erased is situated opposite the slot 3| the eraser is actuated merely by pressing upon the key 33. Then the key bar 3| swingsruponits pivot l34 so that the vertical rod 33 which isconnected by the pivot 33 with the bar 3|, is moved upward, thereby extending the spring 33. 'I'he eraser 33 carried by the upper vertical end of the rod 33 is moved along with the rod and the operative surface 31 of the eraser is passed over the letter or the character to be erased. The pressure of the eraser 33 against the paper is sumcient to erase the character, since such pressure is caused by the substantially strong leaf springs 33 and 33 which press against the prongs 32 and 33 of the vertical bar 33.

After the upward movement of the bar 33 has been completed, the spring 33 pulls the key bar 3| back into the position shown in Figure 2, so

` typed character in front of the slot 3|.

anexa? that the eraser l. moves once again over the letter or character to be erased.

In most instances the letter or character is erased completely after the key Il! has been depressed once. It is possible, however, to repeat this operation several times, provided that prior to each actuation of the key 5l, the letter or character to be erased is placed in front ofthe slots 3| and 64. y

The carriage I2 and the platen I3 move automatically one space forward immediately after a letter or character has been imprinted upon the paper by one of the type levers Il. If at that time the operator nnds that an error has been made, the operator has to strike by hand the back space key 42a in order to bring the incorrectly Then the operator strikes the eraser key Il and thereby erases the incorrectly typed character.

In accordance with the present invention, this necessity of operating the back space lever 43 prior to the erasing may be eliminated through the provision of a device which automatically moves the carriage I2 one space back after the eraser key 5l) has been actuated and before the eraser 66 moves in front of the slot 3|.

This device for automatically moving backward the carriage I2 at the time the eraser key il is actuated is illustrated in Figures 3, 4, 5, and 8 of the drawings, and comprises a lever 'Il having a horizontal portion 10a extending at right angles to the central axis of the platen Il, a vertical portion 10b, another horizontal portion 10c, and a bent end lia which is situated adjacent the portion D of the vertical bar 6B. 'Ihe lever 'l0 extends to the back of the carriage and is movable around a pivot I2 carried by support 1I which is may constitute an integral part thereof, and which' is provided with an inclined surface 11. 'I'he surface 11 engages the end 1|a of the lever I0 i as the bar 60 is moved upwardly in the direction of the arrow 18, thereby causing the lever 'I0 to turn around its pivot 12. Since the pin 'I5 connects the lever 1I! with the lever Il, the movement of the lever 'I0 is transmitted to the lever 44 which is provided with a projection 90 engaging an inclined surface 9|. The projection 90 will slide along the surface 8| causing the hook l5 of the lever M to engage a tooth of the rack 48 and to move the carriage one space backward. This movement is substantially completed before the eraser 66 is moved in front of the slot 3|, so that the eraser is brought into contact with the letter or character to be erased.

The projection 'I6 remains in contact with th lever I0 during substantially the entire movement of the bar 6D, so that no further movement of the carriage I2 takes place and no other letters or characters are smeared by the eraser. jection 16 is moved out of contact with the lever 'I0 when the bar 60 returns to its original position shown in Figure 3.

An important advantage of the present invention is that the erasing attachment constitutes an integral part of the typewriter and is operated by the depression of a key in the same manner in which the other keys are operated. The attachment does not interfere with the usual construc tion of the typewriter and requires merely the addition oi' one key'upon the keyboard.

Furthermore, iny accordance with the present invention, the necessity of moving the carriage by hand one spaceback prior to the erasing may be eliminated, since the movement of the eraser bar may automatically vactuate the back spacer mechanism and r move the carriage one space backward before the eraser isbrought into contact with the letter or character to be erased.

l. In a typewriting machine having a frame, means movable relativelyvto said frame and supporting a sheet of paper, a plurality oi types and means causingsaidtypesto carry out a striking movement against the lint-mentioned means to print a characterupon said sheet, the path of movement of the types adjacent the first-mentioned means being the same for all types in relation to said frame; an eraser support having two prongs at one of the ends thereof, a space being formed between said prongs which is situated in said path in the inoperative position of said support, and an eraser casing adapted to contain an eraser and connected with said prongs, said eraser casing being situated outside of said path in said inoperative position of the support; means carried by said frame and engaging at least one of said prongs, the last-mentioned means being adapted to press the eraser contained in saideraser cssing against the sheet of paper, means connected with said eraser support to move the same out oi' its inoperative position, whereby said eraser casing is moved into said path to cause the eraser to erase an incorrectly typed character, and $5 means connected with the last-mentioned means to move said eraser support back into its inoperative position.

2. In a typewriter machine having a frame, means movable relatively to said frame and supporting a sheet of paper, a plurality of types and means causing said types to carry out a striking movement against the first-mentioned means to print a character upon said sheet, thev path`of movement of the types adjacent the nrst-mentioned means being the same for all types in relation to said frame; a vertical eraser support having two prongs at the upper end thereof, a space being formed between said prongs which is situated in said path in the inoperative position of said support, and an eraser casing adapted to contain an eraser and connected with said prongs, said eraser casing being situated below said path in said inoperative position oi' the support, a spring engaging one of said prongs and adapted to press the eraser contained in said eraser casing against the sheet of papermeans connected with said eraser support to move the same upward out of its inoperative position, whereby said eraser casing is moved into said path to cause the'eraser to erase an incorrectly typed character, and means connected with the last-mentioned means to move said eraser sur.\- port downward and' back into its inoperative position.

y3. In a typewriting machine having typing keys, means supporting a sheet of paper, means moving the first-mentioned means one space forward upon the actuation of each key, and means for moving` the' mst-mentioned means one space backward; a support adapted to carry an eraser, means connected with said support to move the same for the purpose oi' causing said eraser to pass over the sheet of paper to obliterate an incorrectly typed character, and means connected with the third-mentioned means and actuated by the moving support to cause the third-mentioned means to move the first-mentioned means one space backward, whereby the incorrectly typed character may be `placed in the path o1'l movement of the eraser.

4. In a typewriting machine having a frame, a plurality of typing keys, means supporting a sheet of paper, means moving the rst-mentioned means one space forward relatively to said frame upon the actuation of each key, and back spacing means for moving the first-mentioned means one space backward relatively to said frame; a support adapted to carry an eraser,v

means connected with said support to move the same for the purpose of causing said eraser to pass over the sheet of paper to obliterate an incorrectly typed character, a lever pivotally mounted upon said AIrame and yoperatively conf nected with the back rspacing means, said lever eraser.

LOUIS WILNER. 

